Calculation of Effective antenna heights(eff_hgt) using the
SRTM3 Terrain Database

version 1.0
Data is available for America, Eurasia and Africa up to 60 degrees North only.
Data holes were filled by interpolation or with DTED0 data.

To ensure proper results, please enter
degrees, minutes and seconds as shown below.
Leading zeros are not required.

Longitude (ex: 281836)

latitude (ex: -152512)

Antenna height (ex: 150)

East/West = /-

North/South = /-

meters agl

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EFFHGT*
EHAAT

EFFHGT is the effective height of the transmitting antenna, which is the height of the antenna above terrain height averaged between distances of 3 to 15 km in the direction of the receiving antenna.
In the absence of effective antenna height data, the
values resulting from this query can be pasted into T01/T02 electronic notice forms.

*FOR ITU NOTIFICATION, USE ONLY EFFHGT

The effective height of the antenna above average terrain (EHAAT) is the average of the antenna heights
above the average terrain (HAATs) for eight radials spaced every 45 degrees of azimuth starting with
true north. The height of the antenna above average terrain (HAAT) is the height of the centre of
radiation of the antenna above the average elevation of the terrain between 3 to 16 km from the antenna
for each radial. EHAAT is only used locally in Region 2.